Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 28: Correlated Electrons: Quantum-Critical Phenomena - Experiment
TT 28.5: Vortrag
Dienstag, 8. März 2016, 11:00–11:15, H21
High Pressure Quantum Oscillation Studies in the Metallised Mott Insulator NiS2 — •Hui Chang1, Jordan Baglo1, Alix McCollam2, Inge Leermakers2, Sven Friedemann3, Xiaoye Chen1, Pascal Reiss1, HongEn Tan1, Monika Gamza4, William Coniglio5, Stanley Tozer5, and Malte Grosche1 — 1Cavendish Laboratory, University of Cambridge, UK. — 2High Field Magnet Laboratory, Nijmegen, The Netherlands. — 3HH Wills Laboratory, University of Bristol, UK. — 4Jeremiah Horrocks Institute, University of Central Lancashire, UK. — 5NHMFL, Tallahassee, Florida, USA.
The transition from a metallic to a Mott insulating state is a long-standing theme of fundamental interest in condensed matter research. One of the most basic questions concerns the evolution of the Fermi surface and carrier mass in the correlated metallic state near the Mott transition. Quantum oscillation measurements present a direct probe of the Fermi surface, and pressure rather than doping should be used as the tuning parameter in this case. We investigate this question in the Mott insulator NiS2, which becomes metallic at a modest pressure of 30kbar. Using the tunnel diode oscillator technique in conjunction with high pressure anvil cells, we have observed quantum oscillations at pressures between 38kbar and 46kbar in magnetic fields up to 31T. This enables us to resolve key elements of the Fermi surface of high pressure NiS2 and to obtain estimates of the effective carrier mass, which is strongly enhanced over band structure values. Moreover, we discuss the evolution of the Fermi surface, carrier effective mass and relaxation time on approaching the Mott transition.